The Britax Frontier 90 Combination Harness-2-Booster boasts the ground-breaking CLICKTIGHT Installation System combined with Britax’s leading Head Safety technologies. The Frontier 90 keeps your growing toddler safe and offers parents the peace of mind of a secure and easy car seat installation each and every time.*

CLICKTIGHT Installation System allows parents to easily achieve a safe and secure installation using the vehicle seat belt throughout the life of the seat, in harness mode, without having to worry about the weight of their child.*

True Side Impact Protection provides deep side walls and a head restraint with energy-absorbing EPP foam to distribute crash forces, shield from vehicle intrusion, and contain the head, neck and body while keeping them “in true” or aligned

Base with SafeCell Technology designed to keep your child safe and secure in a crash by compressing and significantly lowering the center of gravity, reducing the forward movement of the car seat

I have two of the same , for twins.. Two for $240